That "block" is the physical representation of the private key containing the miner's reward plus fees for Block number mentioned. Those physical collectibles have their private keys laser-etched and with a hologram covering it. So if you peel it off, this reveals the private key which you can use to claim the "virgin" BTC which was mined in that old block.
This also means that it'll have a bunch of forked coins including 25 BCH, 25 BTG etc etc.
Ah, I see, so that miner basically only used one address/key for that block reward then assigned it to the physical collectible.